Isothermal flow mixing calorimeter

Gmehling (1993) measured excess enthalpies of mixing of different liquids in a commercial isothermal flow calorimeter (Hart Scientific 7501) with an uncertainty of less than 1%. The flow mixing tube was thermostatized by constant Peltier cooling and controlled electrical pulse heating to keep the temperature constant. 

The enthalpy change associated with formation of a thermodynamically ideal solution is equal to zero. Therefore any heat change measured in a mixing calorimetry experiment is a direct indicator of the interactions in the system (Prigogine and Defay, 1954). For a simple biopolymer solution, calorimetric measurements can be conveniently made using titra-tion/flow calorimeter equipment. For example, from isothermal titration calorimetry of solutions of bovine P-casein, Portnaya et al. (2006) have determined the association behaviour, the critical micelle concentration (CMC), and the enthalpy of (de)micellization. 

Setaram C80 heat flow calorimeter sample mass, polyisocyanate 264 mg, polyol 292 mg crucible, mixing cell with metallic membrane isothermal at 80 °C, sensitivity 1 jiV. Initially, the two reagents are isolated by a membrane and stabilized in the calorimeter at 80 °C. The membrane is cut, and mixing is effected by manual rotation of the stirrer. 

This dynamic technique used by Oscarson and co-workers [21] at Brigham Young University (USA) to study CO2 capture studies was developed in same University by Christensen and coworkers [71]. The principle of isothermal compensation calorimeter is based on the measurement of an external heat power used to maintain a reaction vessel at constant temperature during mixing. In flow mode the fluids flow to the... 

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